The present proposal requests an additional year of support to complete an ongoing project as originally planned. The research seeks to determine 1) if behavioral and developmental abnormalities associated with iron deficiency anemia during infancy can be corrected with extended iron therapy and 2) if deficits persists in school-aged children who had iron deficiency anemia as infants has been 30% lower than projected, an additional year is needed to enroll the required sample and achieve the project's first goal. Recent studies have found that infants with iron deficiency anemia obtain lower mental and motor test scores than nonanemic controls and that the majority of anemic infants do not show improvement in test scores, even though their anemia is corrected after 2-3 months of iron therapy. to pursue these findings, two studies are in progress. Study I, which will require another year to complete, is a double-blind randomized controlled study of extended iron therapy in infancy. 90 one- to two-year-old infants will be studied: 30 iron deficient anemic infants, matched by age and sex with 30 nonanemic placebo-treated controls and 30 nonanemic iron-treated controls. their behavior and development are being assessed before and after both three and six months of oral iron therapy. The study also provides an opportunity to confirm the specific patten of limitations, observed among iron deficient anemic infants in previous projects. There are two major possible outcomes of the study: 1) an extended course of iron therapy will correct developmental and behavioral abnormalities n iron deficient anemic infants, a result that would require a major reformulation of current recommendations about iron therapy and monitoring of therapeutic response in infants or 2) pretreatment deficits will persist in iron deficient anemic infants despite extended treatment, indicating that, depending on chronicity, severity, or timing, iron deficiency anemia in infancy may have irreversible effects. In Study II all 191 children in the previous cohort are being reassessed at five years of age using psychoeducational, neurological, motor, and behavioral measures that focus on the specific functions that were identified as impaired in our previous two studies. The proposed research will determine the long-term cognitive, motor, and behavioral sequelae of iron deficiency anemia in infancy and the effects of treatment in a group of children that has already been exceptionally well characterized.